Influence of Water Stress on Expression of the X95950 Gene and Several Cellular Callus Components in Violet-Treated Sunflower Varieties

Abstract

The research was conducted between 2017 and 2019 at the College of Agricultural Engineering Sciences and Laboratory of Plant Tissue Culture for Postgraduate Studies at the University of Baghdad. One experiment used a totally random design. The experiment examined the effects of PEG (Polyethylene glycol) at concentrations of 0, 2, 4, 6, and 8% on the development of three sunflower types (Ishaqi-1, Aqmar, and AL-Haja) exposed to UV-C rays for 40 minutes as a result of the growing of the juvenile peduncle outside the live body. The aim of the study was to better comprehend the physiological and biochemical changes caused by water stress on the callus of several sunflower varieties. The X95950 gene was amplified using qPCR technology to investigate drought tolerance gene expression and callus cell content of glutathione, ascorbic acid, and APX enzyme as indicators to determine the effect of PEG on callus tissue cells in the nutrient medium. The expression of the X95950 gene was influenced by water stress. It was particularly expressed in Ishaqi-1 at 4 and 8% PEG concentrations, with values of 1.64 and 1.01, respectively. The glutathione content and activity of the enzyme ascorbate peroxidase, which were 56.49 mol-1 and 0.149 mg-1 protein absorption units, differed significantly among the varieties. PEG concentrations significantly influenced glutathione content, with 8% achieving the highest average of 50.07 mol g-1 and 4% achieving the highest averages of ascorbic acid and ascorbate peroxidase enzyme activity of 2.462 mg 100 g-1 and 0.138 mg-1 protein absorption units, respectively. The interaction was considerable, with the maximum average glutathione callus content in the Aqmar variety reaching 69.60 mol g-1 at 6% PEG concentration. At 4% PEG concentration, the Aqmar variety outperformed in terms of APX enzyme efficacy, reaching 0.238 mg-1 absorption units of protein.